Scroll compressor provided with a discharge port deflector

ABSTRACT

The scroll compressor (1) includes a compressor shell (2) having a discharge outlet (4); a fixed scroll (7) arranged within the compressor shell (2) and including a fixed base plate (11) and a discharge passage (16) which is formed in the fixed base plate (11) and which is provided with a discharge port (17) emerging into a discharge pressure volume (18) at least partially defined by the compressor shell (2) and the fixed scroll (7); and a deflector (29) arranged in the discharge pressure volume (18), the deflector (29) covering the discharge port (17) and at least partially delimiting a discharge opening (31) facing the discharge outlet (4) of the compressor shell (2), the deflector (29) being configured to force a compressed refrigerant gas flow emerging from the discharge port (17) to smoothly shift from an axial direction to a radial direction and being configured to direct said compressed refrigerant gas flow towards the discharge outlet (4).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims foreign priority benefits under 35 U.S.C. § 119to French Patent Application No. 20/12478 filed on Dec. 1, 2020, thecontent of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The invention relates to a scroll compressor provided with a deflectorarranged in a discharge pressure volume delimited by a fixed scroll anda compressor shell.

BACKGROUND

JP 07189966 A shows a scroll compressor provided with a deflectingdevice arranged in a discharge pressure volume and configured to changethe direction of a compressed refrigerant gas flow emerging from thecompression chambers from a direction parallel to the longitudinal axisof the scroll compressor to a direction orthogonal to the longitudinalaxis of the scroll compressor. By guiding the compressed refrigerant gasflow towards side walls of the discharge pressure volume, a directimpingement of the compressed refrigerant gas on the upper end wallsurface of the compressor shell is avoided. Hence, pulsation noise isreduced.

As a discharge fitting is formed in the upper end wall of the compressorshell, the compressed refrigerant gas is subjected to additional changesin its flow direction before leaving the discharge pressure volume. Thisleads to significant pressure drop in the compressed refrigerant gas.

US 2019/0195224 A1 discloses a scroll compressor provided with a mufflerattached to the fixed scroll base plate and covering a discharge portformed in the central portion of the fixed scroll. Also here, a directflow of compressed refrigerant gas to the upper end wall of thecompressor shell is avoided. However, this solution leads again toincreased pressure drop in the compressed refrigerant gas, as severalchanges of the compressed refrigerant gas flow direction occur, beforethe compressed refrigerant gas leaves the muffler chamber through adischarge hole and flows towards the discharge outlet of the compressorshell.

SUMMARY

It is an object of the present invention to provide an improved scrollcompressor, which can overcome the drawbacks encountered in conventionalscroll compressors.

Another object of the present invention is to provide a scrollcompressor with improved efficiency by reducing the pressure losses inthe discharge pressure volume.

Another object of the present invention is also to reduce acoustic noiseemitted from the compressor shell.

According to the invention such a scroll compressor includes:

a compressor shell having a discharge outlet,an orbiting scroll arranged within the compressor shell and comprisingan orbiting base plate and an orbiting spiral wrap extending from theorbiting base plate,a fixed scroll arranged within the compressor shell and comprising afixed base plate and a fixed spiral wrap extending from the fixed baseplate, the fixed and orbiting spiral wraps defining, with the fixed andorbiting base plates, compression chambers, the fixed scroll furthercomprising a discharge passage which is formed in the fixed base plateand which is provided with a discharge port emerging into a dischargepressure volume at least partially defined by the compressor shell andthe fixed scroll, anda deflector arranged in the discharge pressure volume, the deflectorcovering the discharge port and at least partially delimiting adischarge opening facing the discharge outlet of the compressor shell,the deflector being configured to force a compressed refrigerant gasflow emerging from the discharge port to shift, and advantageously tosmoothly shift, from an axial direction to a radial direction and beingconfigured to direct, and particularly to guide, said compressedrefrigerant gas flow towards the discharge outlet.

As the deflector extends over the discharge port and is configured todirect the compressed refrigerant gas flow towards the discharge outlet,a direct impingement of the compressed refrigerant gas flow on an upperend wall of the compressor shell is avoided and the compressedrefrigerant gas is not subjected to several changes in its flowdirection before leaving the discharge pressure volume, whichsubstantially reduces the pressures losses in the discharge pressurevolume while suppressing pulsations and resonating waves between thecompressor shell and the discharge port.

Consequently, the acoustic behavior and the efficiency of the scrollcompressor according to the present invention are substantially improvedcompared to the acoustic behavior and the efficiency of the compressorsof the prior art. Particularly, large improvements (up to −4 dB) havebeen observed, especially for frequencies at 2.5 kHz.

The scroll compressor may also include one or more of the followingfeatures, taken alone or in combination.

According to an embodiment of the invention, the discharge passageextends substantially parallel to the longitudinal axis of the scrollcompressor.

According to an embodiment of the invention, the discharge passage isconfigured to fluidly connect the compression chambers to the dischargepressure volume.

According to an embodiment of the invention, the discharge port isprovided at a central part of the fixed base plate of the fixed scroll.

According to an embodiment of the invention, the discharge outlet isprovided on an upper cap of the compressor shell. Advantageously, thedischarge outlet is provided on a side wall of said upper cap.

According to an embodiment of the invention, the deflector has an elbowshape.

According to an embodiment of the invention, the deflector is attachedto the fixed base plate of the fixed scroll.

According to an embodiment of the invention, the deflector is attachedto a base plate face of the fixed base plate facing away from thecompression chambers.

According to an embodiment of the invention, the deflector includes afirst end sealingly attached to the fixed base plate of the fixedscroll, and a second end at least partially delimiting the dischargeopening.

According to an embodiment of the invention, the first end of thedeflector is sealingly attached to the fixed base plate of the fixedscroll near the discharge port.

According to an embodiment of the invention, the discharge openingemerges into the discharge pressure volume at a predetermined separatingdistance from the discharge outlet to allow communication between thecompressed refrigerant gas flow and the discharge pressure volume.

According to an embodiment of the invention, the scroll compressorfurther includes a discharge check valve assembly attached to thedischarge outlet of the compressor shell and configured to preventbackflow of refrigerant from an external tubing of a refrigerationsystem into the discharge pressure volume, when the scroll compressorstops.

According to an embodiment of the invention, the discharge check valveassembly comprises a tubular valve housing having an inlet openingemerging into the discharge pressure volume and an outlet openingemerging outside the compressor shell and configured to be fluidlyconnected to the external tubing of a refrigeration system.

According to an embodiment of the invention, the discharge opening facesthe inlet opening of the tubular valve housing and is located at apredetermined spacing distance from the inlet opening of the tubularvalve housing.

According to an embodiment of the invention, a ratio between thecross-section of the inlet opening and the cross-section of thedischarge opening is between 0.8 and 1.2, and for example between 0.9and 1.1. In other words, the inlet opening of the tubular valve housingand the discharge opening are similar in size.

According to an embodiment of the invention, the discharge opening andthe inlet opening are configured such that a majority of the compressedrefrigerant gas leaving the discharge port of the fixed scroll isdelivered directly into the inlet opening of the tubular valve housing.Such a configuration of the discharge check valve assembly and thedeflector allows to reduce pressure losses in the compressed refrigerantgas flow.

According to an embodiment of the invention, the discharge passageincludes a wall portion having a curved convex surface portion directedtowards the discharge outlet, and advantageously towards the dischargecheck valve assembly and particularly towards the inlet opening of thetubular valve housing.

According to an embodiment of the invention, the deflector and thecurved convex surface portion of the discharge passage define a smoothsurface structure. Such a configuration of the deflector and thedischarge passage allows to further reduce pressure losses. This isespecially important when using low density refrigerants, e.g. low GWPrefrigerants, as an increased volume flow is required to maintain agiven cooling capacity.

According to an embodiment of the invention, the deflector includes anupper wall part having an inner deflecting surface portion which isconcave and curved, the inner deflecting surface portion being directedtowards the discharge outlet. Such a configuration of the dischargepassage allows to further reduce pressure losses in the compressedrefrigerant gas flow.

The deflector may be manufactured as sintered, pressed, punched,machined or molded metal component. Preferably, the deflector is made asa molded or 3D-printed plastic component.

Advantageously, the deflector is attached to the fixed scroll by use ofscrews or bolts. However, other suitable methods, e.g. welding, brazing,press fitting or gluing may be applied to attach the deflector to thefixed scroll.

These and other advantages will become apparent upon reading thefollowing description in view of the drawing attached heretorepresenting, as non-limiting examples, embodiments of a scrollcompressor according to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of embodiments of the invention isbetter understood when read in conjunction with the appended drawingsbeing understood, however, that the invention is not limited to thespecific embodiments disclosed.

FIG. 1 is a longitudinal section view of a scroll compressor accordingto the invention.

FIG. 2 is a partial longitudinal section view of the scroll compressorof FIG. 1 showing a discharge check valve assembly in a closed position.

FIG. 3 is a partial longitudinal section view of the scroll compressorof FIG. 1 showing the discharge check valve assembly in an openposition, and in which a discharge passage includes a wall portionhaving a chamfer.

FIG. 4 is a partial longitudinal section view of the scroll compressorof FIG. 1 showing the discharge check valve assembly in an openposition, and in which the discharge passage includes a wall portionhaving a curved convex surface portion.

FIG. 5 is a partial top view of the scroll compressor of FIG. 1.

FIG. 6 is a perspective view of a deflector of the scroll compressor ofFIG. 1.

DETAILED DESCRIPTION

FIG. 1 describes a scroll compressor 1 according to the inventionoccupying a vertical position.

The scroll compressor 1 includes a compressor shell 2 provided with asuction inlet 3 configured to supply the scroll compressor 1 withrefrigerant to be compressed, and with a discharge outlet 4 configuredto discharge compressed refrigerant. The discharge outlet 4 isadvantageously provided on a side wall of an upper cap of the compressorshell 2.

The scroll compressor 1 further includes a support arrangement 5 fixedto the compressor shell 2, and a compression unit 6 disposed inside thecompressor shell 2 and supported by the support arrangement 5. Thecompression unit 6 is configured to compress the refrigerant supplied bythe suction inlet 3. The compression unit 6 includes a fixed scroll 7,which is fixed in relation to the compressor shell 2, and an orbitingscroll 8 supported by and in slidable contact with a thrust bearingsurface 9 provided on the support arrangement 5.

The fixed scroll 7 includes a fixed base plate 11 having a lower faceoriented towards the orbiting scroll 8, and an upper face opposite tothe lower face of the fixed base plate 11. The fixed scroll 7 alsoincludes a fixed spiral wrap 12 projecting from the lower face of thefixed base plate 11 towards the orbiting scroll 8.

The orbiting scroll 8 includes an orbiting base plate 13 having an upperface oriented towards the fixed scroll 7, and a lower face opposite tothe upper face of the orbiting base plate 13 and slidably mounted on thethrust bearing surface 9. The orbiting scroll 8 also includes anorbiting spiral wrap 14 projecting from the upper face of the orbitingbase plate 13 towards the fixed scroll 7. The orbiting spiral wrap 14 ofthe orbiting scroll 8 meshes with the fixed spiral wrap 12 of the fixedscroll 7 to form a plurality of compression chambers 15 between them.Each of the compression chambers 15 has a variable volume whichdecreases from the outside towards the inside, when the orbiting scroll8 is driven to orbit relative to the fixed scroll 7.

The fixed scroll 7 further comprises a discharge passage 16 which isformed in a central part of the fixed base plate 11 and which is fluidlyconnected to the compression chambers 15. The discharge passage 16extends parallel to the longitudinal axis of the scroll compressor 1,and is provided with a discharge port 17 emerging into a dischargepressure volume 18 defined by the compressor shell 2 and the fixedscroll 7. Therefore, the discharge passage 16 is configured to fluidlyconnect the compression chambers 15 to the discharge pressure volume 18.

Furthermore, the scroll compressor 1 includes a drive shaft 19 whichextends vertically and which is configured to drive the orbiting scroll8 in an orbital movement, and an electric driving motor 21, which may befor example a variable-speed electric driving motor, coupled to thedrive shaft 19 and configured to drive in rotation the drive shaft 19about a rotation axis A.

The scroll compressor 1 further includes a discharge check valveassembly 22 attached to the discharge outlet 4 and fluidly connected tothe discharge pressure volume 18. The discharge check valve assembly 22is particularly configured to prevent backflow of refrigerant from ahigh pressure side of a refrigeration system, into the dischargepressure volume 18, when the scroll compressor 1 stops.

The discharge check valve assembly 22 includes a tubular valve housing23 inserted in the discharge outlet 4 of the compressor shell 2 andhermetically secured to the discharge outlet 4. The tubular valvehousing 23 has a first end portion 23.1 arranged inside the dischargepressure volume 18 and provided with an inlet opening 24 emerging intothe discharge pressure volume 18, and a second end portion 23.2 arrangedoutside the compressor shell 2 and provided with an outlet opening 25emerging outside the compressor shell 2 and configured to be fluidlyconnected to an external tubing of the refrigeration system. Accordingto the embodiments shown on the FIGS. 1 to 6, the second end portion23.2 of the tubular valve housing 23 acts as a fitting to connect theexternal tubing of the refrigeration system.

The discharge check valve assembly 22 further includes a valve seat 26located within the tubular valve housing 23 and formed at the innersurface of the tubular valve housing 23. The valve seat 26 is annularand extends around the inlet opening 24. Advantageously, the valve seat26 is provided on the first end portion 23.1.

The discharge check valve assembly 22 also includes a valve member 27arranged within the tubular valve housing 23 and movable between aclosed position (see FIG. 2) in which the valve member 27 bears againstthe valve seat 26 and an open position (see FIG. 3) in which the valvemember 27 is remote from the valve seat 26.

The discharge check valve assembly 22 further comprises a biasingelement 28, such as a spring element, configured to bias the valvemember 27 towards the closed position.

The scroll compressor 1 also includes a deflector 29 arranged in thedischarge pressure volume 18 and covering the discharge port 17. Thedeflector 29 may be manufactured as sintered, pressed, punched, machinedor molded metal component. However, the deflector 29 is preferably madeas a molded or 3D-printed plastic component.

The deflector 29 includes a first end 29.1 sealingly attached to theupper face of the fixed base plate 11 of the fixed scroll 7 and locatednear the discharge port 17, and a second end 29.2 at least partiallydelimiting a discharge opening 31 facing the discharge outlet 4 of thecompressor shell 2 and the inlet opening 24. According to theembodiments shown on the figures, the discharge opening 31 is delimitedby the fixed base plate 11 of the fixed scroll 7 and the second end 29.2of the deflector 29. However, the discharge opening 31 may for exampleby entirely delimited by the second end 29.2 of the deflector 29.

Advantageously, the deflector 29 is attached to the fixed scroll 7 byuse of screws or bolts. However, other suitable methods, e.g. welding,brazing, press fitting or gluing may be applied to attach the deflector29 to the fixed scroll 7.

According to the embodiments shown on the figures, the deflector 29 hasan elbow shape and includes an upper wall part 32 having an innerdeflecting surface portion which is concave and curved and which isdirected towards the discharge outlet 4.

The deflector 29 is configured to direct a compressed refrigerant gasflow emerging from the discharge port 17 towards the discharge outlet 4,and particularly towards the outlet opening 25 of the tubular valvehousing 23. The deflector 29 is also configured to force said compressedrefrigerant gas flow to smoothly shift from an axial direction to aradial direction, with respect to the longitudinal axis of the scrollcompressor.

According to the embodiments shown on the figures, the discharge opening31 faces the inlet opening 24 of the tubular valve housing 23 andemerges into the discharge pressure volume 18 at a predeterminedseparating distance D1 from the discharge outlet 4 and is located at apredetermined spacing distance D2 from the inlet opening 24 of thetubular valve housing 23, to allow communication between the compressedrefrigerant gas flow and the discharge pressure volume 18, and to easemounting of the discharge check valve assembly 22 in relation to thedeflector 29. The predetermined spacing distance D2 is between 2 and 40mm, and advantageously between 10 and 30 mm. However, the dischargeopening 31 and the inlet opening 24 are configured such that a majorityof the compressed refrigerant gas leaving the discharge port 17 of thefixed scroll 7 is delivered directly into the inlet opening 24 of thetubular valve housing 23.

A ratio between the cross-section of the inlet opening 24 and thecross-section of the discharge opening 31 is between 0.8 and 1.2, andadvantageously between 0.9 and 1.1, such that the inlet opening 24 ofthe tubular valve housing 23 and the discharge opening 31 are similar insize.

According to the embodiment shown on FIG. 4, the discharge passage 16includes a wall portion 33 having a curved convex surface portiondirected towards the inlet opening 24 of the tubular valve housing 23.Advantageously, the inner surface of the deflector 29 and the curvedconvex surface portion of the discharge passage 16 define a smoothsurface structure. Such a configuration of the deflector 29 and thedischarge passage 16 allows to further reduce pressure losses. This isespecially important when using low density refrigerants, e.g. low GWP(Global Warming Potential) refrigerants, as an increased volume flow isrequired to maintain a given cooling capacity.

However, according to alternative embodiments of the invention, thedischarge passage 16 may includes a wall portion 33 defined by a chamfer(see FIG. 3) or a wall portion 33 being cylindrical (see FIG. 2).

The operation of the scroll compressor 1 will now be described.

When the scroll compressor 1 according to the invention is turned on,the orbiting scroll 8 is driven by the drive shaft 19 following anorbital movement, this movement of the orbiting scroll 8 causing anintake and compression of refrigerant in the compression chambers 15.The compressed refrigerant gas exits toward the discharge pressurevolume 18 via the discharge passage 16 and the discharge port 17 formedin the central part of the fixed scroll 7, is guided towards the inletopening 24 of the tubular valve housing 23 by the deflector 29, movesthe valve member 27 into the open position against the biasing forceexerted by the biasing element 28, and then flows through the tubularvalve housing 23 and the outlet opening 25 of the tubular valve housing23.

Due to the configuration of the deflector 29, the wall portion 33 of thethe discharge passage 16 and the inlet opening 24 of the tubular valvehousing 23, pressure losses in the compressed refrigerant gas aresignificantly reduced, which significantly improves the efficiency andthe performance of the scroll compressor 1.

When the scroll compressor 1 according to the invention is stopped, thebiasing element 28 biases the valve member 27 toward the closedposition, which prevents high-pressure refrigerant from returning to thedischarge pressure volume 18.

Of course, the invention is not restricted to the embodiments describedabove by way of non-limiting examples, but on the contrary itencompasses all embodiments thereof.

While the present disclosure has been illustrated and described withrespect to a particular embodiment thereof, it should be appreciated bythose of ordinary skill in the art that various modifications to thisdisclosure may be made without departing from the spirit and scope ofthe present disclosure.

What is claimed is:
 1. A scroll compressor including: a compressor shellhaving a discharge outlet, an orbiting scroll arranged within thecompressor shell and comprising an orbiting base plate and an orbitingspiral wrap extending from the orbiting base plate, a fixed scrollarranged within the compressor shell and comprising a fixed base plateand a fixed spiral wrap extending from the fixed base plate, the fixedand orbiting spiral wraps defining, with the fixed and orbiting baseplates, compression chambers, the fixed scroll further comprising adischarge passage which is formed in the fixed base plate and which isprovided with a discharge port emerging into a discharge pressure volumeat least partially defined by the compressor shell and the fixed scroll,and a deflector arranged in the discharge pressure volume, the deflectorcovering the discharge port and at least partially delimiting adischarge opening facing the discharge outlet of the compressor shell,the deflector being configured to force a compressed refrigerant gasflow emerging from the discharge port to shift from an axial directionto a radial direction and being configured to direct said compressedrefrigerant gas flow towards the discharge outlet; wherein the deflectorhas an elbow shape; wherein the deflector is attached to the fixed baseplate of the fixed scroll; and wherein the deflector includes an upperwall part having an inner deflecting surface portion which is concaveand curved, the inner deflecting surface portion being directed towardsthe discharge outlet.
 2. (canceled)
 3. (canceled)
 4. The scrollcompressor according to claim 1, wherein the deflector includes a firstend sealingly attached to the fixed base plate of the fixed scroll, anda second end at least partially delimiting the discharge opening.
 5. Thescroll compressor according to claim 1, wherein the discharge openingemerges into the discharge pressure volume at a predetermined separatingdistance from the discharge outlet to allow communication between thecompressed refrigerant gas flow and the discharge pressure volume. 6.The scroll compressor according to claim 1, further including adischarge check valve assembly attached to the discharge outlet of thecompressor shell and configured to prevent backflow of refrigerant froman external tubing of a refrigeration system into the discharge pressurevolume, when the scroll compressor stops.
 7. The scroll compressoraccording to claim 6, wherein the discharge check valve assemblycomprises a tubular valve housing having an inlet opening emerging intothe discharge pressure volume and an outlet opening emerging outside thecompressor shell and configured to be fluidly connected to the externaltubing of a refrigeration system.
 8. The scroll compressor according toclaim 7, wherein the discharge opening faces the inlet opening of thetubular valve housing and is located at a predetermined spacing distancefrom the inlet opening of the tubular valve housing.
 9. The scrollcompressor according to claim 7, wherein a ratio between thecross-section of the inlet opening and the cross-section of thedischarge opening is between 0.8 and 1.2, and for example between 0.9and 1.1.
 10. The scroll compressor according to claim 7, wherein thedischarge opening and the inlet opening are configured such that amajority of the compressed refrigerant gas leaving the discharge port ofthe fixed scroll is delivered directly into the inlet opening of thetubular valve housing.
 11. The scroll compressor according to claim 1,wherein the discharge passage includes a wall portion having a curvedconvex surface portion directed towards the discharge outlet.
 12. Thescroll compressor according to claim 11, wherein the deflector and thecurved convex surface portion of the discharge passage define a smoothsurface structure.
 13. The scroll compressor according to claim 2,wherein the deflector includes a first end sealingly attached to thefixed base plate of the fixed scroll, and a second end at leastpartially delimiting the discharge opening.
 14. The scroll compressoraccording to claim 3, wherein the deflector includes a first endsealingly attached to the fixed base plate of the fixed scroll, and asecond end at least partially delimiting the discharge opening.
 15. Thescroll compressor according to claim 2, wherein the discharge openingemerges into the discharge pressure volume at a predetermined separatingdistance from the discharge outlet to allow communication between thecompressed refrigerant gas flow and the discharge pressure volume. 16.The scroll compressor according to claim 3, wherein the dischargeopening emerges into the discharge pressure volume at a predeterminedseparating distance from the discharge outlet to allow communicationbetween the compressed refrigerant gas flow and the discharge pressurevolume.
 17. The scroll compressor according to claim 4, wherein thedischarge opening emerges into the discharge pressure volume at apredetermined separating distance from the discharge outlet to allowcommunication between the compressed refrigerant gas flow and thedischarge pressure volume.
 18. The scroll compressor according to claim2, further including a discharge check valve assembly attached to thedischarge outlet of the compressor shell and configured to preventbackflow of refrigerant from an external tubing of a refrigerationsystem into the discharge pressure volume, when the scroll compressorstops.
 19. The scroll compressor according to claim 3, further includinga discharge check valve assembly attached to the discharge outlet of thecompressor shell and configured to prevent backflow of refrigerant froman external tubing of a refrigeration system into the discharge pressurevolume, when the scroll compressor stops.
 20. The scroll compressoraccording to claim 4, further including a discharge check valve assemblyattached to the discharge outlet of the compressor shell and configuredto prevent backflow of refrigerant from an external tubing of arefrigeration system into the discharge pressure volume, when the scrollcompressor stops.